JP2024055760A - Valve device - Google Patents

Abstract

[Problem] To provide a valve device that facilitates the handling of parts provided on a valve shaft and facilitates manufacturing. [Solution] A valve device that includes a plate-shaped drive gear 15 at the end of a metal valve shaft 10, and a detection object 21 of an inductive sensor that detects the rotation angle of the valve shaft 10 on the drive gear 15, in which the drive gear 15 has a metal lever member 33 integrated with the drive gear 15 by insert molding with a portion exposed on the inner surface, and the detection object 21 is integrated with the lever member 33 on the outer surface side of the drive gear 15 by insert molding, and an exposed portion 38 of the lever member 33 of the drive gear 15 including the lever member 33 and the detection object 21 is brought into contact with the end of the valve shaft 10 and fixed by laser welding the back side of the abutment from the outer hole 39 side to form a shaft unit. [Selected Figure] Figure 7

Description

The present invention relates to a rotation angle detection structure for a valve device that detects the rotation angle using an inductive sensor.

Many valves, such as a throttle valve, are equipped with an opening sensor that detects the opening of the valve. For example, an inductive sensor (non-contact sensor) that detects the rotation angle (rotational position) of the valve shaft is used as the opening sensor.
An inductive sensor has a detectable object made of a conductor such as metal on the valve shaft, and a sensor coil located close to the conductor. A current is passed through the sensor coil to generate a high-frequency magnetic field, and the inductance of the sensor coil, which changes as the detectable object moves through the magnetic field, is detected to detect the rotation angle of the valve shaft.
For example, in the valve device described in Patent Document 1, the detection object of the inductive sensor is formed from a thin metal plate, and the detection object is assembled to a rotor unit fixed to the valve shaft.

JP 2017-173089 A

However, as in Patent Document 1, the object to be detected in an inductive sensor is often a relatively small part made of a thin plate. Therefore, when assembling the object to be detected to the rotor unit, care must be taken when handling it so that it is not bent or damaged, which creates the problem of laborious assembly. Another problem is that care must be taken when storing the object to be detected as a part so that it is not damaged.

The present invention was made in consideration of these problems, and aims to provide a valve device that has a non-contact sensor detection object on the valve shaft, which makes it easier to handle the parts attached to the valve shaft and makes it easier to manufacture.

To achieve the above object, the valve device of the present invention is a valve device that includes a plastic plate-shaped gear at the end of a metal shaft that drives a valve body, and a detection object of a non-contact sensor that detects the rotation angle of the shaft on the gear, and the gear has a metal support member that is integrated by insert molding with at least a portion exposed on one side, and the detection object is integrated with the gear together with the support member by insert molding on the other side of the gear, and the exposed portion of the support member on the gear after the insert molding is welded to the end of the shaft to form a shaft unit.

Preferably, the gear has an exposure hole that exposes at least a portion of the other side of the support member, and the exposed portion of the support member is brought into contact with the end of the shaft, and laser light is irradiated from the other side of the gear through the exposure hole to the back side of the abutting portion of the support member with the shaft, thereby welding the support member to the shaft.

Preferably, the object to be detected is hollow and surrounds the exposure hole.

Preferably, the gear has an insertion hole into which the end of the shaft can be inserted at any relative rotational position around the axis.

Preferably, the valve device is a throttle valve that controls the amount of intake air into the internal combustion engine.

According to the valve device of the present invention, the gear attached to the shaft that drives the valve body is insert molded to include a metallic support member and a detection object of the non-contact sensor. The shaft unit is then constructed by welding the exposed portion of the support member in the gear including the support member and the detection object to the end of the shaft. Therefore, since the detection object of the non-contact sensor is already included in the gear before welding by insert molding, handling is easy even if the detection object is small.

In addition, the shaft unit can be easily manufactured by welding the exposed portion of the support member in the gear to the end of the shaft.

1 is a perspective view of a valve device according to an embodiment of the present invention; FIG. 2 is a vertical cross-sectional view of the valve device according to the embodiment. FIG. 2 is a perspective view of a valve shaft unit. FIG. 4 is a diagram showing components of a drive gear in a valve shaft unit. FIG. 4 is a perspective view of a drive gear in the valve shaft unit. FIG. 2 is a perspective view of a drive gear and a valve shaft in a valve shaft unit. FIG. 4 is an explanatory diagram showing a method of fixing a drive gear and a valve shaft.

One embodiment of the present invention will be described below with reference to the drawings.

Figure 1 is a perspective view of a valve device 1 according to one embodiment of the present invention. Figure 2 is a vertical cross-sectional view of the valve device 1 according to this embodiment. Note that Figure 2 is a cross-sectional view of part A-A shown in Figure 1.

The valve device 1 of one embodiment of the present invention is, for example, a throttle valve, which is installed in the intake passage of an internal combustion engine to control the amount of intake air.

As shown in Figures 1 and 2, the valve device 1 is provided with an electric motor 4 and a reduction gear 5 in a casing 3 in which a fluid passage 2 that is part of the intake passage is formed. The valve device 1 also includes a valve body 6 that opens and closes the fluid passage 2, and a valve shaft 10 (shaft) that is rotatably supported by the casing 3 and disposed so as to cross the fluid passage 2. The valve body 6 is fixed to the valve shaft 10.

The reduction gear 5 is composed of a motor gear 11 fixed to the output shaft of the electric motor 4, an intermediate gear 12 rotatably supported on the casing 3, and a drive gear 15 (gear) fixed to one end of the valve shaft 10. Power is transmitted from the electric motor 4 to the motor gear 11, intermediate gear 12, and drive gear 15 in that order, driving the valve shaft 10 to rotate.

A return spring 16 is provided adjacent to the drive gear 15 near one end of the valve shaft 10. The return spring 16 is a torsion coil spring wound around the valve shaft 10, with one end engaged with the drive gear 15 and the other end engaged with the casing 3. The return spring 16 biases the valve shaft 10 in one rotational direction.

The casing 3 is provided with two stoppers (not shown) that abut against the drive gear 15. The stoppers limit the rotation angle of the valve shaft 10 to within a predetermined angle range (e.g., 90 degrees).

When the electric motor 4 is not energized, the valve shaft 10 rotates due to the biasing force of the return spring 16, and the fluid passage 2 is fully closed (or fully opened) by the valve body 6. When the electric motor 4 is energized, the valve shaft 10 rotates against the biasing force of the return spring 16, and the rotation of the valve body 6 adjusts the amount of intake air flowing through the fluid passage 2.

An inductive sensor 20 (non-contact sensor) that detects the rotation angle (rotational position) of the valve shaft 10 is provided at one end of the valve shaft 10 on the drive gear 15 side.

The inductive sensor 20 comprises a metallic object to be detected 21 provided on the drive gear 15, and a sensor body 22 fixed to the casing 3 and positioned close to and facing the object to be detected 21.

The sensor body 22 of the inductive sensor 20 includes, for example, a sensor coil, and generates a high-frequency magnetic field by passing a current through the sensor coil. The inductance of the sensor coil changes as the object to be detected moves through the magnetic field, and thus the rotation angle of the valve shaft 10 is detected.

Figure 3 is a perspective view of the valve shaft unit 30. Figure 4 is a diagram showing the components of the drive gear 15 in the valve shaft unit 30. Figure 5 is a perspective view of the drive gear 15 in the valve shaft unit 30. Figure 6 is a perspective view of the drive gear 15 and the valve shaft 10 in the valve shaft unit 30. Figure 7 is an explanatory diagram showing a method of fixing the drive gear 15 and the valve shaft 10. Note that Figure 7 is a vertical cross-sectional view of the fixed portion of the drive gear 15 and the valve shaft 10.

As shown in Figures 3 and 4, the valve shaft unit 30 is composed of a metallic valve shaft 10 and a drive gear 15. The drive gear 15 is composed of a resin gear portion 31, a detection object 21 of the inductive sensor 20, and a metallic lever member 33 (support member).

The gear portion 31 is a substantially disk-shaped component made of resin, and a gear 35 (e.g., a spur gear) is formed over approximately half (approximately 180 degrees) of the outer periphery. At both circumferential ends of the outer periphery where the gear 35 is formed, a stopper abutment surface 36 is provided, which abuts against a stopper (not shown) provided on the casing 3 to restrict rotation. At the center of the inner surface of the gear portion 31 (the surface opposite to the surface facing the sensor main body 22: one side surface in the present invention), a circular shaft mounting hole 37 (insertion hole) into which the valve shaft 10 is inserted is provided (see Figures 2, 6, and 7). The shaft mounting hole 37 has a diameter slightly larger than the outer diameter of the valve shaft 10. Inside the shaft mounting hole 37, the center of the lever member 33 is exposed (exposed portion 38 shown in Figure 7).

The center of the outer surface of the gear portion 31 (the surface facing the sensor body 22: the other surface in the present invention) is provided with an outer hole 39 (exposed hole) that is smaller in diameter than the shaft mounting hole 37 and larger in diameter than the valve shaft 10. The center of the gear portion 31 is penetrated by the outer hole 39 and the shaft mounting hole 37.

The object to be detected 21 is a thin plate with a generally circular plate shape with a hollowed-out center, and has six radial members 40 extending in the radial direction, three inner circumferential members 41 extending in the circumferential direction to connect the ends of the radial members 40 on the center side, and three outer circumferential members 42 extending in the circumferential direction to connect the ends of the radial members 40 on the outer side. The radial members 40, the inner circumferential members 41, and the outer circumferential members 42 all have a width and thickness of about several mm. The radial members 40 are arranged at equal intervals in the circumferential direction, with the ends on the center side of every other member being connected by the inner circumferential members 41, and the outer ends being connected by the outer circumferential members 42, which are offset in the circumferential direction from the inner circumferential members 41.

The object to be detected 21 is disposed on the outer surface of the gear portion 31 on the outer hole 39 side, coaxially with the center of the gear portion 31. In addition, the radially outer end surface of the inner circumferential member 41 of the object to be detected 21 and the edge of the outer hole 39 of the gear portion 31 are located at approximately the same radial position.

A groove 45 is formed on the outer surface of the gear portion 31 to accommodate the outer circumferential member 42 and the radial member 40.

The lever member 33 is a flat metal plate that is embedded inside the gear portion 31. The lever member 33 has a circular central hole 50 in the center that is smaller than the outer diameter of the valve shaft 10. One end of the valve shaft 10 is provided with a cylindrical protrusion 51 that protrudes in the axial direction, and this protrusion 51 is inserted into the central hole 50 of the lever member 33. The central hole 50 of the lever member 33 has a smaller diameter than the radially inner end face of the inner circumferential member 41 of the detection object 21.

The lever member 33 also has three arc holes 52 that extend in an arc shape around the central hole 50. The three arc holes 52 have approximately the same shape and size as the inner circumferential member 41 of the object to be detected 21, and are arranged so as to be located at approximately the same radial and circumferential positions as the inner circumferential member 41.

As shown in FIG. 5, the gear portion 31, lever member 33, and object to be detected 21 are integrated by insert molding to form a single component, the drive gear 15. The gear portion 31 is formed from resin, with the metal lever member 33 and object to be detected 21 as insert parts. In other words, the lever member 33 and object to be detected 21 are combined when the resin molding of the gear portion 31 is completed.

As shown in FIG. 6, the valve shaft 10 is fixed to the drive gear 15, which includes the lever member 33 and the object to be detected 21, to manufacture the valve shaft unit 30.

More specifically, as shown in FIG. 7, one end of the valve shaft 10 is inserted into the shaft mounting hole 37 of the gear portion 31 of the drive gear 15, one end of the valve shaft 10 is abutted against the exposed portion 38 of the lever member 33 exposed from the shaft mounting hole 37, and the protrusion 51 of the valve shaft 10 is inserted into the center hole 50 of the lever member 33.

7, a laser beam is applied to the lever member 33 exposed in the outer hole 39 from the outer surface side of the drive gear 15, to weld the lever member 33 and the valve shaft 10. The position of the laser beam is the back side of the contact surface between one end of the valve shaft 10 and the lever member 33. This laser welding may be performed around the entire circumference of the protrusion 51, or may be performed at three points on the inside of the arc hole.

This produces a valve shaft unit 30 having a drive gear 15 including the lever member 33 and the object to be detected 21, and a valve shaft 10.

As described above, in the valve device 1 of this embodiment, the drive gear 15 is fixed to the end of the valve shaft 10 to which the valve body 6 is fixed in order to transmit power from the electric motor 4.

In this embodiment, the drive gear 15 has a metal lever member 33 formed by insert molding inside the resin gear portion 31. The gear portion 31 is also provided with the detectable body 21 of the inductive sensor 20. The detectable body 21 is also built in together with the lever member 33 when the gear portion 31 is manufactured. Therefore, the drive gear 15 integrated with the lever member 33 and the detectable body 21 is manufactured as a part.

The drive gear 15, which has the lever member 33 and the object to be detected 21, is fixed to the end of the valve shaft 10 by laser welding, thereby fixing the drive gear 15 to the valve shaft 10.

This allows the drive gear 15 including the object to be detected 21 to be manufactured as a part and prepared in advance. Although the object to be detected 21 itself is a small part, having it already be included in the drive gear 15 makes it easier to handle. Then, for example, when assembling the valve device 1, the valve shaft unit 30 can be easily manufactured by fixing the drive gear 15 including the object to be detected 21 by laser welding.

After insert molding, the drive gear 15 has a shaft mounting hole 37 on one side (inner side) where the center of the lever member 33 is exposed, and an outer hole 39 on the other side (outer side) where the back side of the exposed portion 38 of the lever member 33 is exposed. When assembling the valve device 1, the end of the valve shaft 10 is abutted against the exposed portion 38 of the lever member 33 visible from the shaft mounting hole 37, and laser light is irradiated from the outer side of the drive gear 15 through the outer hole 39 to the back side of the abutting portion of the lever member 33 with the valve shaft 10, welding the lever member 33 and the valve shaft 10. This makes it easy to fix the drive gear 15 and the valve shaft 10 together.

Furthermore, the object to be detected 21 is hollow so as to surround the outer hole 39. Therefore, when laser light is irradiated from the outer hole 39 side of the drive gear 15 to the back side of the contact portion between the lever member 33 and the valve shaft 10, the laser light can be irradiated by passing through the hollow portion of the object to be detected 21 and the outer hole 39.

The end of the valve shaft 10 has a circular cross section, and the shaft mounting hole 37 into which the valve shaft 10 of the drive gear 15 is inserted is also a circle larger than the valve shaft 10, so that the end of the valve shaft 10 can be inserted at any relative rotational position (rotational angle) with respect to the drive gear 15. Therefore, the drive gear 15 can be fixed at any rotational position with respect to the rotational position of the valve body 6 with respect to the valve shaft 10. This makes it possible to manufacture valve shaft units 30 with different mounting angles for the drive gear 15 using one type of drive gear 15 and valve shaft 10.

This concludes the description of the embodiment, but the aspects of the present invention are not limited to the above embodiment. For example, the detailed shapes of various components, such as the shape of the gear portion 31 of the drive gear 15, may be changed as appropriate.

In the above embodiment, the present invention is applied to a throttle valve, but the present invention can be applied to various valve devices other than a throttle valve.

1 Valve device 6 Valve body 10 Valve shaft (shaft)
15 Drive gear (gear)
20 Inductive sensor (non-contact sensor)
21: Object to be detected 30: Valve shaft unit 33: Lever member (support member)
37 Shaft mounting hole (insertion hole)
38 Exposed portion 39 Outer hole (exposed hole)

Claims (6)

A valve device comprising a plate-shaped resin gear at an end of a metal shaft that drives a valve body, and a detection target of a non-contact sensor that detects a rotation angle of the shaft is provided on the gear,
The gear has a metal support member that is integrated by insert molding with at least a portion of the metal support member exposed on one side surface,
the detection object is integrated with the gear together with the support member by the insert molding process on the other side surface of the gear,
a shaft unit is formed by welding an exposed portion of the support member of the gear after the insert molding process and an end portion of the shaft. the gear has an exposure hole that exposes at least a part of the other side surface of the support member,
2. The valve device according to claim 1, characterized in that the exposed portion of the support member and an end portion of the shaft are brought into contact with each other, and laser light is irradiated from the other side of the gear through the exposed hole to the back side of the contact portion of the support member with the shaft, thereby welding the support member and the shaft. 3. The valve device according to claim 2, wherein the detection object is formed into a hollow shape so as to surround the periphery of the exposure hole. 4. The valve device according to claim 1, wherein the gear has an insertion hole into which the end of the shaft can be inserted at any relative rotation position about the axis. 4. The valve device according to claim 1, wherein the valve device is a throttle valve that controls an intake amount of an internal combustion engine. 5. The valve device according to claim 4, wherein the valve device is a throttle valve for controlling an intake amount of an internal combustion engine.